I just purchased MoI the other day and I'm really enjoying it - especially the beta.

I had a couple of questions that I didn't see in the FAQ.

First, I understand how to create Objects so I can hide, unhide and select them. But is there a way to group or nest these objects? Right now I'm working on a piano model. I have several key Objects defined, but now I'd like to group them so I can hide them while I work on other parts of the piano.

Secondly, I absolutely love the Fillet tool in MoI but I run into difficulties with it frequently. The problem I have is, sometimes I end up with edges that shoot off into space when a bevel crosses a perpendicular edge. Are there any tutorials or documentation on getting good Fillet's?

Finally, I have been exporting OBJs from MoI into 3D Coat for painting, but 3D Coat is complaining that the UVs are incorrect (too large is the error I think I've seen). Is there a way to edit the UVs prior to export to fix this?

There is a scene browser to use for this... You can use named objects or styles. When you slect something, if you clcik the name in the upper right, you can name it. Then it will be an object down in the objects section. The eye is for hide/show, and there is a far right dot for selection. Think of styles like layers, and the show/hide/selection is the same. Types will target edges/solids/faces etc....

> Right now I'm working on a piano
> model. I have several key Objects defined, but now I'd like
> to group them so I can hide them while I work on other
> parts of the piano.

The easiest way to do that currently is to assign a name to those objects, which you do by selecting them and then clicking on the name line in the properties panel in the upper-right corner of the main window here (where it says "unnamed" which shows the current object name):

Once you have assigned your objects a name (you can have more than one object assigned to the same name to make a type of group), there will then be an entry in the scene browser "Objects" section with that name in it and you can use the eye icon there to hide and show that object set.

> Secondly, I absolutely love the Fillet tool in MoI but I run into
> difficulties with it frequently. The problem I have is, sometimes
> I end up with edges that shoot off into space when a bevel
> crosses a perpendicular edge.

Can you please post an example file for the problem?

Fillet pieces that shoot off like that are usually caused by some difficulty in the fillet calculation step where it tries to intersect 2 fillet pieces with one another. One situation where that can tend to happen is if your model is constructed with pieces that come within a few degrees of being tangent to one another but are still not quite tangent. Intersection calculations between things that are set up like that become more difficult.

But it's hard to know for sure what you ran into without seeing an example file - filleting involves a lot of various difficult calculations so there are quite a variety of different things that can make it have problems, it's hard to know for sure which particular thing you ran into without seeing your specific example.

> Finally, I have been exporting OBJs from MoI into 3D Coat for
> painting, but 3D Coat is complaining that the UVs are incorrect
> (too large is the error I think I've seen). Is there a way to edit
> the UVs prior to export to fix this?

Hmmm, I have not actually heard of this error before - but basically the UVs that MoI creates on export are really basic - every surface has UVs but they all map to the same full 0,0 to 1,1, unit texture square, so basically every surface shares the same texture area. If you want to paint on an object and have different paint show up on different surfaces, you will need to make a different uv mapping on it where each mesh has its own separate small region of the texture square rather than them all sharing the same region.

MoI does not itself have any tools for editing the UVs - usually polygon modeling programs have the tools to do that part. I think 3D-Coat has some tools for doing that, it's discussed some here:http://3d-coat.com/uv-mapping/

You'll basically want to throw out MoI's default UV coordinates and have 3D-coat create a new UV structure that is more suited for painting, you'll probably do that by using the "unwrap" function in 3D-coat to generate the UVs.

There are also some specialized programs that just do UV editing, like:

I must be a little confused. Are you saying to name each of my objects, then take all those name objects, select them and then give them all a name to create a group?

What I'm trying to do is set up some rudimentary hierarchical structure to my objects so I can more easily navigate through them all. Basically I wanted to have each key as a named object, then put them into a parent folder called "keys".

As far as the fillet problem, it's exactly as you're describing. I'll attach an image to show you what I mean. I'm assuming it's just a matter of me coming from polygonal modeling and so I'm probably doing wrong.

That's just a quick example I threw together, but I see this effect often.

Hi Paul - currently there is not any way to group things using nested hierarchies, that is something that I want to add in v3.

But you can group things into different labeled sets - that's what doing the object naming can give to you.

So for example if you have some particular set of objects that you know you want to hide and show repeatedly in the future, assign that set of objects a name and then you will be able to go to the scene browser and hide/show/lock/select that object set using the scene browser controls to do it rather than clicking on the items in the viewport window.

> Basically I wanted to have each key as a named object, then put
> them into a parent folder called "keys".

You can do the "each key as a named object" part right now, but not the parent folder part.

> As far as the fillet problem, it's exactly as you're describing. I'll
> attach an image to show you what I mean. I'm assuming it's just
> a matter of me coming from polygonal modeling and so I'm
> probably doing wrong.

Could you please attach the 3DM model file instead of just the screenshot? It's really hard to analyze the geometric properties of just a screenshot - in order to figure out what might be wrong I really need to examine the model more closely than I can with a screenshot.

The particular thing I'd probably be looking for first in a case like you show there though is whether the edges you are filleting actually meet up smoothly with each other at those places where the fillets are not intersecting properly. They probably are not meeting smoothly there, and when 2 edges do not meet smoothly the fillet system will try to extend the fillets and intersect them with each other. If they meet at a really shallow angle like around 5 degrees or so it tends to be a difficult case to intersect well.

The solution for cases like that is to make sure your initial curves that you used to create the objects were actually smooth to one another instead of just eyeballed to be close to smooth but actually having a slight shallow corner between them.

So if you have the original curves you used to create that model it would also help if you could include those in the 3DM file as well so I could take a look at them too.

But my best guess that I could make just from the screenshot is that it looks like probably not enough accuracy in the initial curve framework - something like curves meeting at a shallow 5 degree angle to one another instead of meeting with a shared tangent. That kind of shallow angle kink can tend to make filleting a lot more difficult for the filleting engine and get that kind of results.

You basically want to spend some time on your initial curve framework to make sure it is high quality - filleting is a particularly sensitive area and it does not tolerate problems in the geometry very well. Among the many kinds of things that it does not like are when 2 fillet sections collide into one another at a shallow angle - it's better for things to either meet up smoothly or to meet up at a more well defined sharp angle rather than something like a shallow 5 degree angle which is close to being smooth but not actually smooth.

Basically, you would create a gap at the edge location by which you would construct the rounded-over corner surface with the Blend tool and other construction methods.
The gap can be created by using Boolean Difference to subtract a the result of a Swept operation. The resultant surface edges are (matched) and then Blended.

It's not a straight-forward and easy procedure since one: some surface edges on your geometry simply need to be addressed for error, and two: some edge curves on the gaps have to be Merged or Trimmed to be matched, and three: the Sweep object used to Difference your geometry to make the gap may have overlapping kinks and can't readily be used unless rebuilt themselves.

This is like using MoI brand duct tape to fix an inherent problem in your geometry, but can keep you from pulling out all of your hair when your stuck trying to get that Filleted edge you desire.